heart anatomy

The heart is a muscular organ about the size of a clenched fist, responsible for pumping blood throughout the body. It has four chambers: two upper atria and two lower ventricles. The right side receives oxygen-poor blood from the body and pumps it to the lungs for oxygen, while the left side receives oxygen-rich blood from the lungs and sends it to the rest of the body. Valves between chambers prevent backflow, ensuring proper blood flow. The heart's electrical system controls its rhythm, making it beat regularly. This coordinated activity maintains circulation, delivering oxygen and nutrients to tissues and removing waste products.